But Che only wore it because of its military connections ~~ from the late-40s - early 50s [when I did Nat Service] it spread from the Royal Tank Regiment [& FM Lord Montgomery who preferred it to his Service Dress cap] in late WWii, to replace the forage cap, which in turn had replaced the cutter-peak cap as the standard military headgear; and so it remains among UK land forces. So a military, rather than a 'radical' [whatever that may be] look was surely Che's aim.